Reenforced-concrete slab structure



Sept. 24, 1929. s. J. BRANsoN REENFORCED CONCRETE SLAB STRUCTURE FiledFeb. l, 1929 NIM. 1 L e Patented Sept. 24, 1929 UNITED STATE-s PATENTlorrlcla.

SAMUEL JOSEPH BRANSON, F EVANSTON, ILLINOIS, ASSIGNOR T0 THE BRANSONSYSTEM, INC., 0F CHICAGO, ILLINOIS, A CGRPORATION OF DELAWAREREENFORCED-CONCRETE 'SLAB STRUCTURE l Application mea February 1, 1929.serial Rassegna My invention relates to horizontalconcrete constructionof a type'adapted for fioors, ceilings, roofs, and the like, and itl*has for its bject the provision of a new and improved form andarrangement of concrete and cooperating reenforcing parts by reason ofwhich an increased span of such structure may safely be employed withoutmaterially increasing the amountor weight of the conlo crete or thereenforcing steel in proportion to tho area as compared with smallerspans heretofore, and without greatly increasing the thickness or depthof the concrete.

'lo these ends, it is one of the objects of my invention to provide anew and improved distribution of the concrete with respect to the reenforcing bars, whereby 'at every point a suicient thickness of concreteis provided fory building up the required compressive stresses wh ile atthe sametime care is taken to prevent the use of concrete in such manneras to in crease the dead weight without adequately increasing thestrength of the structure. It is one of the objects of my invention toprovide a new and improved arrangement comprising a panel supported bylongitudinally extending supports such as beams, partitions, or thelike, at itsopposite sides, with the marginal portions of the spanadjacent to 5o the supports at the sides in the form of plain slabswithout auxiliary reenforcing beams extending transversely thereof, theintermediate portion of the panel between the reenforced marginalportions being in the form of 35 a combined slab and beam structure.

lt is another Aobject of my invention to provide an improved arrangementin a structure of this type in which reenforcing steel bars extendcontinuous substantially from the 4o beam or other support at one sideof the panel or section to the beam at the opposite side, servingeffectively as the bottom tension hars for the beams at theintermediate. combination slab andv beamportion of the span andalsoserving effectively for building up bottom compressive stresses forthebeamless slab structure portion adjacent to the outside beams orother supports.

It is one of the objects of my invention to 5.0 provide a constructionin which a horizontal concrete structure is supported from beams at itsfour sides, with `the central portion of the span arranged to supportitsnormal load partially from the beams and partially from the marginalportions of thespan, and with said marginal portions of the spanadjacent to the beams at the Sides of the span of' differentAarrangement and reenforced more strongly for supporting from the beamsboth their own load and a portion of the load carried by theintermediate portion of the span. It is one of my objects to provide astructure of this type in which the effective thickness of the slabportion of the structure is decreased by ste s from a point adjacent tothe side beam to t e point of inflection, whereby j the use of surplusand ineffective concrete at the central portion of the span shall beavoided.

It' is another object of my invention to provide an improved arrangementof parts comprising two concrete slab portions of different thicknessformed integrally with each other, lwith a reenforcing bar extending'along the edge of the thicker slab portion substantially at its bottomface, being' held in position by a pad or rib of concrete formedintegrally with the slab portion, whereby substantially the fullthickness of the thicker slab portion serves to build up effectivediagonal tension and compression stresses respectively in connectionwith said reenforcing bar. Y

vIt is another object of my invention to improve constructions of thistype in sundry details hereinafter pointed out. The preferred means by-which Ihave accomplished my several objects are illustrated in thedrawing andare hereinafter specifically described. Thatwhich I believeto'be new and desire to cover by Letters Patent is set forth in theclaims.v

In the drawing-,

Fig. 1 is a top plan view of a quadrilateral section of a Hoor embodyingthe preferred form of my improvements, with one corner broken away, andshowing fragmentary portions o the adjacent sections; -l

Fig. 2 is a vertical sectional view,` taken substantially at line 2 2 ofFig. 1, being shown upon an enlarged scale;

Figs. 3 and 4 areweitical sectional views taken at the lines 3 3 and 4 4respectively of Fig. 2; and

Fig. 5 is a vertical sectional view taken at line' 5 5 of Fig. 1.

Referring to the several gures of the drawing, in which correspondingparts are indicated by the same reference cliaractcis, 10, 11, 12 and 13indicate upright supports of any approved type arranged inquadrilatei'al spaced relation with respect to cach other. Between thesupports at each of the four sides of the section, I liave lprovidedcomparatively deep beams 14 of any approved type supported at their endsfrom the columns 10, 11, 12 and 13. Tlie space between the beams 14 isbridged by a concrete slab structure comprising a plurality of slabportions of different forms as hereinafter set forth, suclr several slabportions being formed integrally with each otlicrand extendingcontinuous over the beams so as to provide with the adjacent sections acant lever construction.

In the construction shown, each of the upright supports is in the formof a conci-ete column reenforced by steel placed in positionprogressively as the pouring ofthe concrete proceeds, as distinguishedfrom a steel skeleton construction employing structural shapes, but myinvention is not limited to this particular type of column. Each of thebeams 14 in the construction shown is reenforced by a horizontallydisposed I-beam 15, and a plurality of reenforcing bars 16 of anyapproved type and disposed in any desired arrangement, but the beams maybe otherwise formed and reenforced if desired.

In the construction shown, I have' employed marginal slab portions 17 ofsubstantial thickness or depth at the sides adjacent to the beams 14such slab portions being formed integrally with the beams. Inside of thethick marginal portions 17, I have providedslab portions 18 of decreasedthickness or depth formed integrally with the slab portions 17, andbetween the slab portions 18 I employ a combination slab and beamstructure 19, of which the beam portions are indicated by numerals 20and the slab por' tions by numerals 21.

For reenforcing the intermediate slab and beam structure and forsupporting it from the beams 14, I have provided top tension bars 22 ateach side of the section, said bars extending across the beams 14 inspaced relation to each other adjacent to the top face of the floor,being placed preferably at the minimum depth necessaryfor effectivefireproofing. These reenforcing bars extend inwardly some littledistance to or a short distance beyond the point of inflection of thecantilever structure. I provide also positive tension bars 23 extendingacross the slab portions 18 at substantially the bottom faces of suchslab portions, such bars being held in position with respect to the slabportions 18 by means of pads 24 of concrete formed integrally with saidslab portions 18, such pads surrounding the bars 23 and serving to bondthem securely to the slab. The bars 23 extend in one direction from theslab portions 18 iiito and through the slab portions 17 and into thebeams 14, and extend in the opposite direction into-and along the bottomportions ofthe beam portions 20 of the combination slab and beamstructure 19.

By the provision of the `comparatively thick slab portions 17 and thebars 23 which serve at these points as negative compression members,diagonal tension is built up to -an adequate degree. By the use of thetop tension bars 22 extendin to or beyond the points of inflection, thesla portions 18 are supported strongly enough to take care of the loadimposed upon them. By tlie use of the reenforcing bars 23 in crossedrelationship in the slab and beam structure, serving as bottom tciisionbars for the beams 20 of such slab and beam structure, the centralportion of the span is afforded ample support from the thicker slabportions 18 and the beams 14 regardless of the fact that the slabportions 21 are made comparatively thin. i

By the use of my improved construction, I .have provided the requisitestrength and stiffness for supporting a span of twenty-one s ortwenty-two feet between lines of centers, with the intermediate slabortion not more than aboutthree inches in t ickness and with thecomplete thickness or depth of the beams of the combinationslab and beamstructure not more than'about six inches.

While I prefer. to employ a construction substantially in conformity tothat shown iii my drawingit is to be understood that my invention is notto be limited thereto except so .far as the claims may be so limited bythe prior art.

I claim 1. In a reenforced an`d fireproofed conci-etc structure, thecombination of two longitudinally extending supportskin spaced relation'to each other, a slabff concrete extending out from each support towardthe other, a reenforcing'bar extending substantially from one support tothe other substantially at the bottom faces of. the slab portions, padsof eoiicreteformed integrally with said slab portions surrounding saidreen'forcing bar serving to bond said bar with t-lie slab portions, aconcrete beam extending across from one of saidsl'ab ortions to theother surrounding `said reenforcinglbar at its lower portion and withits upper face flush with the upper faces of said slab portions` andmeans formed integrally with said slab portions and said beaml atopposite sides of the beam bridging the space between said first namedslab portions.

2. In a reenforeed and fireproofed concrete structure, the combinationof two longitudina-lly extending supports in spaced relation to eachother, a plurality of reenforcing bars extending in spaced relation toeach other substantially' from one support to the other, a slab ofconcrete extending out from each support above said reen'forcing barswith the bars located substantiallyat the bottom faces of the slabportions, pads of concrete formed integrally with said slab portionssurrounding said reenforcing bars serving to protect said bars and tobond them with said slab portions, concrete beams extending across fromone slab portion to the other flush at their upper faces with the upperfaces of the slab portions and surrounding said reenforeing hars attheir lower portions, and slab portions bridging from one beam to thenext between said first named slab portions, said second named slabportions being of decreased. thickness as compared with said first namedslab portions.

3. A reenforeed concrete structure comprising in combination a slab ofconcrete, a combination slab and beam structure formed integrally withsaid first named slab, with the second named slab and beam portionsmerged into said first named slab, said first named slab being ofgreater depth than the second named slab portion, a reenforcing barextending along the edge of said first named slab portion atsubstantially the bottom face of said first named slab, and a pad ofconcrete formed integrally with said first named slab on its bottom facesurrounding said reenforcing bar serving to protect the bar and to bondit to said slab.

4. A reenforeed concrete structure, comprising in combination two slabportions of different thickness formed integrally with each other withtheir top faces flush` a reenforcing bar extending along the edge of thethicker slab portion substantially at the bottom face thereof, and a padof concrete formed integrally with said thicker slab portion on itsbottom face surrounding said reenforcing bar and holding it in fixedposition with respect to said slab.

5. A reenforced concrete structure, comprising in combination two slabportions of different thickness formed integrally with each other withtheir top faces fiush, a reenforcing bar extending along the edge of thethicker slab portion substantially at the bottom face thereof, a pad ofconcrete formed integrally with said thicker slab portion on its bottomface surroundin g said reenforcing bar and holding it in fixed positionwith respect to said slab, and a plurality of top tension bars in thetop surface portion of said 'combined slab structure at substantiallyright angles with respect to said first named rcen orcing bar. y

6. A reenforeed concrete structure, couiprising in combination two slabportionsI o l different thickness formed integrally with each other withtheir top faces flush, a reenforcing bar extending along thel edge ofthethicker slab portion substantially at the bottom face thereof, aplurality of bottom tension bars at substantially the bottom face ofsaid thicker slab portion at substantially right angles with respect tosaid first named reenforcing bar, and pads of concrete formed integrallywith said thicker slab portion on its bottom face surrounding saidreenforeing bars and holding them in fixed position with respect to theslab.

7 A reenforeed concrete structure, comprising in combination two slabportions of different thickness formed integrally With each other withtheir top faces fiush, a rcenforcing bar extendin along thc edge of thethicker slab portion su stantiall at the bottom face thereof, aplurality of top tension bars in the top surface portion of' saidcombined slab structure at substantially right an les with respect tosaid first named reen orcing bar, a plurality of bottom tension bars atsubstantially the bottom faces of said thicker slab ,portion atsubstantially right angles with respect to said first named re.enforcing bar, and pads of concrete formed integrally with said thickerslab portion on its bottom face surroundin said reenforcing bars andholding them in hgxed position with respect to the slab.

8. A reenforeed concrete structure, comprising in combination two slabportions of different thickness formed integrally with each other withtheir top faces Hush, a reenforcing bar extending along the edge of thethicker slab portion substantially at the bottom face thereof, aplurality of bottom tension bars at substantially the bottom face ofsaid thicker slab portion at substantially right angles with respect tosaid first named reen orcing bar, pads of concrete formed integrallyWith said thicker slab-portion on its bottom face surrounding saidreenforcing bars and holding them in fixed position With respect to saidslab, and beams formed integrally with said thinner slab and comprisingportions thereof and merged at their ends With the edge of said thickerslab, said bottom tension bars being surrounded by said beams at theirlower portions.

9. A reenforeed concrete structure, comprising in combination two slabportions of different thickness formed integrally with' each other withtheir top faces fiush, a reenforeing bar extending along the edge of thethicker slab portion substantiall at the bottom face thereof, aplurality o top tension bars in the top surface portlon of said combinedslab structure at substantially right an les with respect to said firstnamed reen orcing bar, a plurality of bottom tension bars atsubstantially the bottom face of said thicker slab portion atsubstantially right angles with respect to said first named reent'orcingbar, pads of concrete formed integrally with said thicker slab portionon its bottom face surrounding said reenforcing bars and holding suchbars in fixed position with respect to the slab, and beams formedintegrally with said thinner slab portion and comprising portionsthereof and merged at their ends With the edge of said thicker slabportion, said bottom tension bars being surrounded by said beams attheir lower portions.

10. A reenforced concrete structure comprising in combination a slab ofconcrete, a combination slab and beam structure formed integrally withsaid first named slab, with the second named slab and beam portionsmerged into said first named slab, said first named slab being ofgreater depth than the second named slab portion, a reenforcing barextending across said thicker slab portion at substantially the level ofthe bottom face of said slab portion and extending into and along thelower portion of one of said beams, and a pad of concrete formedintegrally with said thicker slab portion on its bottom face surroundingsaid reenforcing bar.

11. A reenforced concrete structure comprising in combination a slab ofconcrete, a combination slab and beam structure formed integrally withsaid first named slab, with the second named slab and beam portionsmerged into said first named slab, said first named slab being ofgreater depth than the second named slab portion, a reenforcing barextending along the edge of said first named slab portion atsubstantially the bottom face of said first named slab, a secondreenforcing bar extending across said first named slab portion andextending into and along the lower portion of one of said beams atsubstantially the bottom face of said first named slab portion, and padsof concrete formed integrally with said first named slab portion on itsbottom face surrounding said reenforcing bars and bonding them to saidslab portion.

12. A reenforeed concrete structure comprising in combination a sla-b ofconcrete, a combination slab and beam structure formed integrally withsaid first named slab, with the second named slab and beam portionsmerged into said first named slab, said first named slab being ofgreater depth than the second named slab portion, a reenforcing barextending along the edge of said first named slab portion atsubstantially the bottom face of said first named slab, a series ofreenforcing bars extending across said first named slab portion andextending into and along the lower portions of said beams atsubstantially the level of the bottom face of said rst named slabportion, and pads of concrete formed integrally with said rst named slabportion on its bottom face surrounding said reenforcing bars and mergingat their ends with said beams.

13. A reenforced concrete structure comprising in combination a slab ofconcrete, a second slab of concrete of decreased thickness formedintegrally with said first named slab, a third slab of concrete of stillsmaller thickness formed integrally with said second slab, a reenforcingbar extending along the edge between said second and third slabssubstantially at the bottom face of the second slab, and a pad ofconcrete formed integrally with said second slab surrounding saidreenforcing bar serving to bond said bar to said slab.

14. A reenforced concrete structure comprising in combination a slab ofconcrete, a second slab of concrete of decreased thickness formedintegrally with said first named slab, a combination slab and beamstructure of concrete formed integrally with said second slab with thebeams merging at their ends into said second slab and of substantiallythe same depth as that of the first named slab and with the slab portionof said combination slab and beam structure of smaller depth than thatof the second slab, reenforcing bars extending across the bottom face ofsaid second slab at substantially the bottom face thereof and extendingin one direction into said first named slab and in the other directioninto and along said beams, and pads formed integrally with said econdslab surrounding said reenforcing 15. A reenforced concrete structurecomprising in combination a slab of concrete, a second slab of concreteof decreased thickness formed integrally with said first named slab, acombination slab and beam structure of concrete formed integrally Withsaid second slab with the beams merging at their ends into said secondslab and of substantially the same depths as thatof the Afirst namedslab and with the slab portion of said combination slab and beamstructure of smaller depth than that of the second slab, reeenforcingbars extending across the bottom face of said second slab atsubstantially the bottom face thereof and extending` in one directioninto said first named slab and in the-other direction into and alongsaid beams, a reenforcing bar extending along the edge between saidsecond and third slab portions substantially at the bottom face of saidsecond slab, and pads formed integrally with said second slabsurrounding said reenforcing bars and serving to bond said bars to saidslab.

.16. A reenforced concrete structure comrising in combination areenforced concrete eam, slabs of concrete connected with said beam atits opposite sides, combination slab and beam structures connected withsaid first inlined slabs, with the beam portions-extending toward saidfirst named beam and With the slab portions of smaller depth than thatof the first named slabs, rcenforcing bars extending across said firstnamed slabs at subslantially their bottom faces and extending` into andalong the beams of said slab and beam structures, and pads formedintegrally with said first named slabs and surrounding said reenforcingbars serving to bond the bars to said slabs.

17. A reenforced concrete structure comprising in combination arcenforced concrete beam, slabs of concrete connected With said beam atits opposite sides, combination slab and beam structures connected withsaid first named slabs, with the beam portions extending toward saidfirst named beam and with the slab portions of smaller depth than thatof the first named slabs, top tension bars extending across said firstnamed beam and into and across said first named slabs into the slab andbeam structures adjacent to their upper faces, other reenforcing barsextending across said first named slabs at substantially their bottomfaces and extending into and along the beams of said slab and beamstructures, and pads formed integrally With said first named slabssurrounding said reenforcing bars serving to bond them to said slabs.

18. A reenforced concrete structure comprising in combination areenforced concrete beam, slabs of concrete connected with said beam atits opposite sides, combination slab and beam structures connected Withsaid first named slabs, with the beam portions extending toward saidfirst named beam and with the slab portions of smaller depth than thatof the first named slabs, reenforcing bars extending across said firstnamed slabs at substantially their bottom faces and extending into andalong the beams of said slab and beam structures, reenforcing bars atopposite sides of said first named beam extending along the edgesbetween the first mentioned slabs and the slab and beam structures atsubstantially the bottom faces of the first mentioned slabs, and padsformed integrally with said first named slabs and surrounding saidreenforcing bars, serving to bond said bars to said slabs.

19. A reenforced lconcrete structure comprising in combination areenforced concrete beam, slabs of concrete connected with said beam atits opposite sides, combination slab and beam structures connected withsaid first named slabs, with the beam portions extending toward saidfirst named beam and with the slab portions of smaller depth than thatof the first named slabs, top tension bars extending across said firstnamed beam and into and across said first named slabs into the slab andbeam structures adjacent to their upper slabs.

SAMUEL JOSEPH BRANSON.

